1. Field of the Invention
The present invention relates to an ultrasonic diagnostic apparatus and a controlling method of the ultrasonic diagnostic apparatus that generates a 3D image from a signal obtained by ultrasonic scanning using an ultrasonic probe.
2. Description of the Related Art
There has been provided a technology called a spatio temporal image correlation (STIC) that calculates a cycle of fluctuation in time of a subject from the 3D data collected in an ultrasonic diagnostic apparatus, and uses the calculated cycle of fluctuation to rearrange and display the data in cardiac cycles.
The STIC has been used mainly for obtaining a 3D image of a fetal heart and, distinctively, may display a movement of a fetal heart in real time without requiring heart-rate synchronization. The STIC uses a mechanically sweeping mechanical 4D probe to read periodical changes of the heart with 4D ultrasound, which is developed for the fetal heart, and thus detect heart rates of the fetus as cardiac cycles (which may be called heart rate value). The STIC is a system which an image is obtained by scanning to the entire heart in approximately 10 seconds, which volume data are synthesized in accordance with the cardiac cycles, and which a moving image constructed by images for one cardiac cycle is established. Since the STIC obtains images of 150 frames in one second, one scanning operation for 10 seconds save the data for 1,500 cross-sectional images. On the basis of the volume data containing approximately 40 cross-sectional images for each cardiac cycle, a 3D image set is reconfigured. The 3D image set is moved in series for 4D display.
An ultrasonic diagnostic apparatus applying the STIC is disclosed in Japanese Patent Application Publication No. 2005-74225.
However, the technology in the past extracts analysis sample data from the entire data contained in the volume data to estimate the cycles of fluctuation. Thus, when, for example, the heart of the fetus is scanned, real cardiac cycles may be different from the estimated cardiac cycles. The reasons for the difference may include that the data extracted as the analysis sample contains data on the other regions in addition to the data on the heart and components, such as a fetal movement and maternal cardiac cycles, excluding the beats of the fetal heart may mix therein as noise. This may lower the precision of the peak detection with autocorrelation or fast Fourier transform (FFT) analysis.
When correct cardiac cycles are not calculated, the technology in the past may require capturing the volume data by performing the 2D scanning (or live scanning) again, which increases the time required for examination.